This invention relates to the field of motor vehicle service, more specifically to the filling and pressure testing of the cooling systems of motor vehicles. The cooling system of a motor vehicle or automobile basically consists of a radiator, motor and the heater core connected by the means of hoses, filled with varying proportions of water and antifreeze liquid, depending upon the climate. Periodic maintenance recommended by the manufacturers requires that the cooling system of all motor vehicles be drained and refilled with fresh fluid.
This invention provides a compact lightweight means to perform these maintenance functions quickly and easily along with removing entrapped air, without the intrusive measures of removing any interconnecting hoses within the system and allowing the excess fluid to return to the container. After connections of hoses have been removed by a service person, no matter how old the vehicle it becomes debatable if any damage to the hoses was done at the time of the removal and who should be responsible for the replacement of the hoses and any other damage incurred when the hoses fail.
Since the advent of the motor vehicle the means of cooling the motor has been a radiator filled with water and interconnected by means of rubber hoses. The heater for the inside of the motor vehicle is coupled with this cooling system with additional rubber hoses to the heater core. The connection of the rubber hoses and the associated parts of the cooling system is commonly made by slipping the rubber hose over a nipple section and affixing a hose clamp over the rubber hose at the union. Early on, antifreeze, composed of ethylene glycol, was developed to inhibit rust and corrosion and to prevent freeze-up and boil over. From the start manufacturers have recommended periodic draining, flushing and refilling of the cooling system, but too often this involved the removal of the radiator because of some form of blockage. There have been a great number of patents issued for machines to perform the task of draining and flushing motor vehicle cooling systems but they are large, cumbersome and require an electrical connection. If the radiator was blocked in any way, it would have to be removed and the core rodded out. Much of the failure in the cooling systems has been caused by the deterioration and contamination of the liquid coolants, causing blockage of the radiator and overheating of the engine with the small ports in a radiator, if there is an appreciable amount of debris in the fluid, more often than not the flushing process will offer only a temporary solution to the problem, and the radiator will soon have to be removed and rodded out.
In the last ten years there has been a noticeable and profound improvement in the reliability of automobile cooling systems. Rarely is a cooing system failure caused by deteriorated or contaminated coolant. This is mainly due to the improved quality of automotive antifreeze, the addition of the radiator overflow tank, and the conscientious maintenance habits of automobile owners.
As most automobile cooling systems are simple to refill after draining for routine servicing or repairs, they do require the technician""s full attention until the cooling system is completely full and the air is bled out through the radiator filler neck. Depending on the make and model of the automobile, this procedure can take between ten to thirty minutes, as the coolant temperature has to be hot enough to open the thermostat, allowing trapped air to escape up to the radiator to be bled off.
Design changes to automobiles have made servicing cooling systems much more difficult and time consuming with some examples being the automobile with a rear engine and the radiator in the front, the radiator with the restricted filling neck, the limited access to the filling neck and the filling neck below the high point of the cooling system. Improperly filled cooling systems can cause engine overheating and damage.
U.S. Pat. No. 4,083,399 of John A. Babish et al. describes an improved flushing apparatus that employs the combination of forces of controlled pressurized water and air turbulence to effect efficient flushing and cleaning of internal combustion engine liquid cooling systems. The ""399 Babish patent tells of a large machine with many controls and functions to drain and flush radiators, it would take up a good deal of space in a shop for a flushing operation that is not used as often as in the past and involves disconnecting existing cooling system hoses at various locations.
U.S. Pat. No. 4,109,703 of John A. Babish et al. relates to flushing of internal combustion engine liquid cooling systems; more particularly, it concerns an air pressure assisted flushing of such systems wherein air bubbles entrained in flushing liquid act to efficiently scavenge or scrub scale and rust from coolant passages. The ""703 patent of Babish is a modification of his first patent and still involves a large machine and involves the cutting and permanently installing fittings for the operation in the rubber hoses of the cooling systems of the automobiles.
U.S. Pat. No. 4,127,160 of Kenneth L. Joffe discloses a method and apparatus for flushing debris from a liquid circulation system such as the cooling system of a water-cooled vehicle. The apparatus includes an inlet conduit for flushing liquid, a series of branch conduits connected to points on the circulation system, a drainage conduit for used water, and a valve or series of valves setable between various positions dictating different flow paths for the flushing liquid through the conduits and the circulation system. The ""160 patent of Joffe is another large device that entails several connections within the circulation system of the engine involving more time to set up and the possibility of damaging the rubber hoses in the system.
The preferred embodiment of this invention consists of a closed-loop refilling and pressure testing system for modern motor vehicle cooling systems comprised of a fluid reservoir with the fill cap incorporating an air release valve. A mounting plate with the handle is attached to the top of the fluid reservoir tank by the means of conventional fasteners and is the base plate whereby all the controls and connections are attached. On the top surface of the mounting plate are: the compressed air fitting, the external hose quick disconnect coupling, a 3-way valve control knob, the line pressure gauge, the return hose connection fitting and the delivery hose connection fitting. The delivery hose with the in-line flow control valve is connected to the nipple on the top of the radiator fill cap adapter. The return hose is connected to the radiator tank overflow nipple on the radiator fill spout of the radiator.
With the 3-way valve control knob in the first position, compressed air enters the compressed air fitting to the compressed air regulator to drive the pneumatic pump. The motor vehicle will have been running long enough to heat the existing antifreeze in the cooling system and the thermostat will be open to allow free flow of the coolant through the system. The pneumatic pump draws the antifreeze fluid through a strainer and pressurizes it to flow through the delivery hose and the flow control valve to the nipple on top of the radiator fill cap adapter. The pressurized antifreeze fluid then passes through the normal channels of the motor vehicle cooling system, consisting of the radiator top tank, the radiator core, the radiator lower tank, the motor and the heater core before returning back through the motor, where it may be somewhat restricted by the thermostat before returning back to the radiator top tank. Various combinations of different routings occur on different makes of vehicles with the same general basic principles involved. Under normal operation of the vehicle the heated antifreeze fluid flows freely through the motor vehicle cooling system with the gasses or expanded fluids passing through the radiator tank overflow nipple through a hose and into a conventional overflow tank. Excess antifreeze fluid and any accumulated gasses displaced by the antifreeze fluid are transferred back to the fluid reservoir tank by the means of the return hose connected to the nipple on the radiator fill spout. The return hose connects to the return hose connection fitting with the antifreeze fluid flowing through the interconnecting tubing into the entrance port of the 3-way valve and out the primary exit port into the fluid reservoir. The secondary exit port of the 3-way valve is closed during this operation With the motor vehicle cooling system filled with antifreeze fluid and most of the accumulated gasses removed, the 3-way valve control knob is turned to the second position. At this position the primary exit port of the 3-way valve is closed and the secondary exit port is opened to allow the flow of the antifreeze fluid into the surging unloading valve where the valve holds back the antifreeze fluid until a predetermined pressure is reached; then it releases the fluid in a substantially instantaneous surge until the pressure is lost. Thereafter the surging and unloading valve resets and begins to hold back and build the pressure again to the predetermined level wherein the cycle repeats itself. This surging action has the unique capability of making the fluid in the system draw or pull along the entrapped gasses within the motor vehicle cooling system and transferring them into the fluid reservoir central cavity. This is especially effective in fluid cooled engines since there are many nooks and crannies in which gas becomes trapped and held in place by the fluid, and using that fluid to draw out the gas or air during fluid surging helps to void the cooling system of gas which inhibits its operation. Also, the slow building of the surging and unloading valve of the system pressure and sudden release thereof stores energy in the flexible hoses used in such systems which is also released when the valve suddenly opens aiding in the purging of the system of gas.
After operating the closed-loop refilling and pressure testing system for modern motor vehicle cooling systems for a predetermined amount of time, the 3-way control knob is turned to the third position with both the primary exit port and the secondary exit port on the 3-way valve closed. In this position the motor vehicle cooling system can be pressure tested by reading the line pressure gauge. Also, with the 3-way valve in this position a hose can be attached to the external hose coupling connected to interconnecting tubing to transfer antifreeze and entrapped gasses into a secondary containment means out of the closed loop system.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent construction insofar as they do not depart from the spirit and scope of the present invention.
An object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to provide a means to refill and pressure test the cooling systems of motor vehicles, especially the modern variety with a filling means lower than some parts of the engine allowing for the entrapment of air within the system.
Another object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to return any excess fluid back to the fill tank along with the entrapped air.
An additional object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to create a pulsating force to remove entrapped air, gas, or solid contaminants, from the system.
A further object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to refill and pressure test motor vehicles with the radiators in remote locations from the engines, as when the engine is in the rear and the radiator is in the front of the vehicle.
Yet another object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to refill and pressure test vehicles with limited access to the filling neck of the radiator.
A further object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to supply a device small and lightweight enough to rest on top of any work bench during the process and can be easily stored.
Still another object of this closed-loop refilling and pressure testing system for modern motor vehicle cooling systems is to supply a device that can operate with air pressure alone, not requiring an electrical hook-up.
Yet another object of this closed-loop refilling and pressure testing system for modern automotive cooling systems is to perform the operations quickly and efficiently without removing any existing hose connections on the vehicle.
These together with other objects and advantages which will become subsequently apparent reside in the details of the construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout.